The present invention relates to the field of data replication.
Significant reliability advantages for a large data processing system can be achieved if the system is broken into a network of smaller systems, each carrying a part of the processing load. This requires that the database copies across the network be kept in synchronization. One method for database synchronization makes use of asynchronous replication of database modifications from the database being changed (the source database) to the other copies of that database in the network (the target databases). If database changes are not applied to the target databases in the same order as they were applied to the source database, serious database inconsistency and corruption can occur. This is especially a problem if the data replication engines are multi-threaded so that database modifications flow from the source databases to the target databases over a multiplicity of independent paths. Various methods are described in the present invention which ensure that data replicated via multi-threaded replication paths do not result in replication-induced database corruption or inconsistency.